Hot-air heating apparatus.



1 No. 666,870. Patehted Jan. 29, mm.

' E. n. JOHNSON.

HOT AIR HEATING APPARATUS.

(Application filed June 1, 1899.)

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Patented Jan. 29, MN.

E. H. JOHNSON. HOT AIR HEATING APPARATUS.

(Applicatiop filed June 1, 1899.) (No Model.) 2 Sheots-Sheet 2.

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Nrran STATES ATENT FFICE.

ENOS H. JOHNSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE ANDREWS & JOHNSONCOMPANY, OF SAME PLACE.

HOT-Al R H EATI N G APPARATU S.

SPECIFICATION forming part of Letters Patent No. 666,870, dated January29, 1901. Application filed June 1, 1899. Serial No. 719,006. (Nomodel.)

To all whom it may concern.-

Be it known that I, ENOS H. JOHNSON, of Chicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Hot-Air Heating Apparatus, of which the following is a specification.

This invention relates to certain improvements in hot-air heatingapparatus, and more particularly to that class of hot-air heatingapparatus where the air is discharged under blast through a stack ofheating coils or pipes and thence into a hot-air chamber, where it ismixed to a greater or less extent with colder air before beingdischarged into the pipes or conduits,by which it is conducted to theapartments to be warmed. As apparatus of this kind is usuallyconstructed the air for heating the building is drawn into a chamber bya fan through primary heating or tempering coils and is then dischargedby the fan through main heating-coils into a hot-air chamber and alsounder or around the main heatingcoils into a tempered-air chamber, thesetwo chambers being located in proximity to each other and communicatingby damper-controlled openings with the conduits which convey heat to thevarious rooms. The dampers in said openings are usually controlledthermostatically and by assuming varying positions admit air from thetwo chambers in such proportional volumes as to afford a heating mediumof a proper temperature to be directed to the apartment.

With apparatus constructed as above described certain difficulties havebeen found in securing the proper temperature of the heating medium atall times. The principal difficulty is due to the inability to maintainthe precise temperature desired in the temperedair chamber. To securethe best results, a uniform temperature of 60 is required to bemaintained in this chamber; but it is practically impossible to soproportion the heatingsurface of the preliminary heating or temperingcoils as to secure uniform results in all con ditions of externaltemperature, an amount of heating-surface adequate in mild weather beingtotally inadequate in colder weather.

It is the purpose and object of my invention to improve this class ofheating apparatus by such changes in the construction as will obviatethe difficulties above mentioned charge 7.

8 represents a chamber into which the fan discharges, the chamber beingclosed at the sides by the walls 9.

10 represents piers of masonry to receive the base 11 of theheating-pipes 12. These pipes may be of any suitable form, but arepreferably round pipes set close together and with a staggeredarrangement. A duct or opening 13 is provided between the piers 10 belowthe heating-pipes 12.

14 represents the hot-air chamber, and 15 the tempered-air chamber,separated by the partition 16, preferably insulated and having a duct oropening 17 therein. The chambers 14 and 15 communicate through openings18 and 19, respectively, with the boots 20 of the separate conduits ordelivery-pipes 21,1eading to the several apartments to be heated.

The openings 13 and 17 are controlled by the connected dampers 23 and24, and said dampers are simultaneously operated from the pressure-motor25 through the lever 26 and link 27. Said motor is supplied with apressure fluid through the pipe 28, and the motor fluid is admitted tosaid pipe through a valve mechanism controlled by the thermostat 29,located within the tempered-air chamber. I have not shown in detail thevalve-controlling mechanism, as devices of this kind are well known inthe art. The

The passages 18 and 19 are controlled by the connected dampers 31 and32, and said dampers are also thermostatically controlled.

In my arrangement I dispense with the preliminary heating or temperingcoils and take the air at outside temperature into the fan and dischargeit into the chamber 8, and thence through the heating coils or pipes 12into the hot-air chamber 14, and through the opening 13 below said coilsor pipes into the tempered-air chamber 15. Thus the air delivered intothe chambers 14 and 15 may be at widely-varying temperatures, and inorder to secure and maintain a uniform temperature of in thetempered-air chamber I provide the opening or passage 17 in the commonwall of said chambers and admit therethrough a sufiicient volume of theheated air from chamber 14 to mix with the cold air in the chamber 15.By providing the damper 23 in the passage 13 and connecting it with thedamper 24 in the passage 17 it is obvious that the flow of the cold airthrough the passage 13 may be restricted and a flow of the hot airthrough the opening 17 accelerated, thus bringing the air in thetempered-air chamber speedily to the required temperature. This requiredtemperature I have stated to be 60, as experience has shown that it isbest to maintain in the tempered-air chamber a temperature approximatingwithin a few degrees that which it is desired to maintain in theapartment to be heated, and

the passage of alternate volumes of heated and cool air, creatingdrafts, is thus avoided.

It will be understood that the connected dampers 31 and 32 will assumevarying positions, according to the temperature requirements of theapartments to be heated, and that a considerable range of movement ofthe connected dampers 23 and 24 may also take place.

There are several advantages attendant upon the use of the apparatusarranged as above described. In the first place the old form ofapparatus depended for its successful operation upon a mathematicalcalculation of the heating-surface contained in the preliminary heatingor tempering coils,which calculation, of course, was based upon anaverage or mean temperature and which necessarily did not take intoaccount extreme or even considerable variations above and below saidmean. The operation of my apparatus is entirely independent of any suchcalculation and is equally certain and uniform under all conditions ofthe external atmosphere. The essential distinction between my inventionand the methods in use heretofore consists in the fact that I admit theair at the external temperature, Whatever it may be, and then secure theuniform desired temperature in the tempered-air chamber by the admissionof heated air from the adjoining chamber, whereas in the olderarrangement it was attempted to deliver into the temperedair chamber airat a practically uniform tern perature. My invention also effects aconsiderable saving in space, as the heating-coils may all be placed onthe discharge side of the fan, and a saving of expense in constructionand maintenance is also elfected.

While I prefer to connect the dampers 23 and 24, they may bedisconnected and separately actuated, and while I prefer tothermostatically control said dampers, yet for the broader purposes ofmy invention they may be manually operated and the thermostat dispensedwith. It will also be understood that the arrangement of thedelivery-dampers 31 and 32 may be altered and that other changes may bemade without departing from the spirit and scope of my invention.

I claim 1. In a hot-air heating apparatus, the combination with anair-heater, of an air-forcing apparatus for delivering air to saidheater, a hot-air chamber into which the heated air is delivered, atempered-air chamber communicating with the hot-air chamber and adaptedto receive heated air therefrom, a by-pass through which a portion ofthe air under blast may be delivered into the tempered-air chamberwithout passing through the heater, and dampers controlling the by-passand the communication between said chambers, substantially as described.

2. In a hot-air heating apparatus, the combination with an air-heater,of an air-forcing apparatus for delivering air to said heater, a hot-airchamber into which the heated air is delivered, a tempered-air chambercommunicating with the hot-air chamber and adapted to receive heated airtherefrom, a by-pass through which a portion of the air under blast maybe delivered into the tempered-air chamber without passing through theheater, and interconnected thermostaticallyactuated dampers controllingthe bypass and the communication between said chambers, substantially asdescribed.

3. In a hot-air heating apparatus, the combination with an air-heater,of an air-forcing apparatus for delivering air to said heater, a hot-airchamber into which the heated air is delivered, a by-pass through whicha portion of the air under blast may pass, a temperedair chamber withwhich said passage connects, a duct or passage between the hot-airchamher and the tempered-air chamber, andinterconnected dampers for thepassages to the tempered-air chamber and between the hotair and thetempered-air chambers, a motor for moving said dampers, and a thermostatlocated in the tempered air chamber for controlling said motor,substantially as described.

4. In an air-heating apparatus, the combination with a fan-blower, aheater, a hot-air chamber adjacent to the heater, a temperedair chamberadjacent to the hot-air chamber and communicating therewith, a by-passleadin g from the fan side of the heater to the tempered-air chamber,dampers for controlling the passages to and from the tempered-airchamber, said dampers being interconnected, a motor for moving saiddampers, a thermostat for controlling said motor located within saidchamber, the hot-air chamber and the tempered-air chamber deliveringintoa common duct or passage, and valves or dampers for controlling theoutlets from said cham- I6 bers, substantially as described.

EN OS H. J OHNSON;

Witnesses:

L. F. MOCREA, E. L. HUBER;

